Related Experiment Video
Updated: Jun 18, 2025
09:59
Functional Reconstitution and Channel Activity Measurements of Purified Wildtype and Mutant CFTR Protein
Published on: March 9, 2015
12.2K
Ribosomal Frameshifting Selectively Modulates the Assembly, Function, and Pharmacological Rescue of a Misfolded CFTR
Patrick Carmody1, Francis J Roushar1, Austin Tedman2
1Department of Chemistry, Indiana University Bloomington, Bloomington, IN, USA 47401.
Biorxiv : the Preprint Server for Biology
|August 2, 2024
Summary
A newly identified RNA structure in cystic fibrosis transmembrane conductance regulator (CFTR) mRNA causes ribosomal frameshifting. This impacts ΔF508 CFTR protein assembly, function, and drug rescue, revealing a link between cotranslational misfolding and translation regulation.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Cotranslational misfolding of cystic fibrosis transmembrane conductance regulator (CFTR) is central to cystic fibrosis (CF) pathogenesis.
- The most common CF variant, ΔF508 CFTR, exhibits altered translational regulation and quality control.
- The direct influence of nascent polypeptide misassembly on translation machinery activity remains unclear.
Purpose of the Study:
- To investigate how nascent CFTR polypeptide misassembly influences translation machinery.
- To identify RNA structural elements within CFTR mRNA that regulate translation.
- To determine the impact of these RNA structures on ΔF508 CFTR function and drug response.
Main Methods:
- Identification of a structural motif in CFTR mRNA that induces -1 ribosomal frameshifting and premature translation termination.
- Analysis of protein-RNA interactions using wild-type and ΔF508 CFTR variants with and without specific RNA structure mutations.
- Assessment of ΔF508 CFTR channel gating and response to CFTR modulators (e.g., Trikafta) in the presence and absence of the ER membrane protein complex (EMC).
Main Results:
- A specific RNA motif in CFTR mRNA stimulates -1 ribosomal frameshifting and premature translation termination.
- Disruption of this RNA structure alters the interaction of nascent ΔF508 CFTR with translation and quality control proteins.
- Modifying the RNA structure enhances ΔF508 CFTR channel function and its rescue by CFTR modulators, an effect dependent on EMC.
Conclusions:
- Ribosomal frameshifting selectively modulates the assembly, function, and pharmacological rescue of misfolded CFTR variants.
- Interactions between the nascent chain, quality control machinery, and ribosomes dynamically tune translation processivity in response to cotranslational misfolding.
- This highlights a novel mechanism linking RNA structure, translation, and CFTR protein homeostasis.
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